Selecting the 4-neighbours of a pixel [closed] - image

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 10 years ago.
How can I select the 4-neighbours of a pixel in matlab?
Thanks.

If the the image is img and the current pixel indices are i and j, then the four neighbors will be:
img(i-1,j);
img(i+1,j);
img(i,j-1);
img(i,j+1);

Related

CUDA dijkstra's algorithm [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 9 years ago.
Has anybody implemented a CUDA parallelization version of Dijkstra's Algorithm for a given sparse matrix (cuSPARSE) graph, and for source, and target node, find the minimal K path?
I really need it to solve a general graph I'll be constructing.
Vincent

Problems in R\P (looking for an example) [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 11 years ago.
I'm studying computability theory, and I'm looking for a problem that clearly can be solved, but not in polynomial time.
I tried thinking of all sort's of examples, but it wasn't clear why they can't be solved in polynomial time..
The travelling sales man problem.

Insertion sort of items in array [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 10 years ago.
In plain English describe the algorithm for an insertion sort of items in an array.
I've also been asked to use diagrams if appropriate but that's a little hard on here I understand.
Here is a PDF presentation which describes insertion sort.
With a quick google search http://en.wikipedia.org/wiki/Insertion_sort

how to crack the DES encryption algorithm [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 12 years ago.
How to break the DES encryption algorithm....using which programming language, it is most efficient.
John the Ripper

Balanced Quad Tree [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 9 years ago.
how can I build a balanced quad tree.
Thanks, Marcos
Balancing is traditionaly a part of "k-D Tree" algorithm, which is superset for octrees. Try e.g. wikipedia page on this algorithm.

Resources